Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D9/00—Chemical paint or ink removers
  • C09D9/005—Chemical paint or ink removers containing organic solvents

Definitions

• the present invention relates to an organic solvent stripper composition, in particular a paint or varnish stripper composition preferably based on methylene chloride.
• the disadvantage of such systems lies in the relatively large amount of polymer which must be dissolved in the methylene chloride solvent.
• the amount of polymer dissolved detracts from the useful solvent power of the solvent stripper, which means that the methylene chloride effectively is rendered more limited in its ability to dissolve the resins contained in the paint film to be stripped.
• the usefulness of the stripping composition is reduced.
• methylene chloride paint stripper compositions containing a film-forming polymer in which the type or amount of polymer is such as to provide a thickening effect, but not a film-forming effect.
• a thickening effect is provided by incorporating a polymer in an amount not sufficient to form a film, together with (as a substance for forming a skin) a filling agent in the form of scales or leaves e.g. talc.
• Specification No. 2,031,447A describes a stripper composition comprising methylene chloride and including a film-forming polymer such as a vinyl acetate or acrylic polymer in an amount insufficient to form a film.
• the stripping power of the methylene chloride is preserved by employing a secondary solvent for the film-forming polymer.
• a secondary solvent may be another organic solvent or water and, in the case of water, the solution of polymer in water is emulsified with the water-immiscible methylene chloride solvent.
• peelable methylene chloride strippers can be prepared in which there is no reduction in the stripping power of the methylene chloride, while at the same time there is formed during use a peelable skin having sufficient strength to remain intact for removal of paint or varnish or like residues, and no other skin-forming substances such as talc are required in the composition.
• the present invention provides a stripper composition, which composition comprises methylene chloride in an amount sufficient to provide the desired degree of stripping action, the methylene chloride being present in an aqueous emulsion containing a film-forming polymer which is a natural or synthetic rubber insoluble or essentially insoluble in methylene chloride, and the rubber being present in an amount sufficient to fc_m a skin when the composition is applied as a layer over a coated surface to be stripped.
• a stripper composition which composition comprises methylene chloride in an amount sufficient to provide the desired degree of stripping action, the methylene chloride being present in an aqueous emulsion containing a film-forming polymer which is a natural or synthetic rubber insoluble or essentially insoluble in methylene chloride, and the rubber being present in an amount sufficient to fc_m a skin when the composition is applied as a layer over a coated surface to be stripped.
• the stripper composition of the invention may be used in a variety of situations where it is desired to remove a coating comprising a solvent-soluble film from a substrate surface. Accordingly, while the invention is particularly applicable to paint stripper compositions, it is to be understood that the invention also embraces 5 ther stripper compositions, including those used for stripping varnish.
• the organic solvent generally will be methylene chloride as indicated above, although other organic solvents could be employed if desired.
• the methylene chloride may be partly or wholly replaced by another organic solvent which is capable of dissolving a paint or varnish or like film, and the rubber is then chosen from those which are insoluble or essentially insoluble in the alternative solvent or solvent mixture employed.
• trichloroethylene for example, may be used at least partly to replace methylene chloride e.g. in an amount of up to about 10% by weight or more.
• the methylene chloride or other solvent will be present in the composition in an amount typically in excess of about 45% by weight, with the upper limit typically being about 85% by weight.
• the amount of methylene chloride is from about 50% to about 80% by weight, more preferably from about 60% to about 70% by weight. It will be understood, however, that the amount of methylene chloride can be varied within a wide range depending on the degree of solvent power required.
• the composition of the invention generally contains a film-forming polymer which is a natural or synthetic rubber, at least essentially insoluble in methylene chloride, or other solvent employed. Furthermore, since such materials are conveniently obtained as aqueous latices, and since water is essential to provide the aqueous emulsified form in which the composition of the invention is presented at least some, and preferably essentially all, of the water present in the composition can be provided as part of a rubber latex.
• the amount of water present in the composition must be sufficient to act as a carrier for the rubber and to form a relatively stable emulsion. Generally, from about 5 to about 20% by weight of water will be present based on the composition, and preferably from about 5 to about 10% by weight of the composition.
• the amount of rubber present in the composition of the invention should be such as to provide an essentially peelable skin on use, and typically will be at least about 5% by weight of the composition. While the upper limit on the amount of rubber present is not critical, for economic reasons it is not likely to exceed about 20% by weight. Preferably, the amount of rubber will be in the range of from about 5 to about 15% by weight of the total composition, e.g. from about 6 to about 10% by weight. Thus, in the case where a rubber latex containing say about 50% to about 60% by weight of solids is employed, the amount of rubber latex in the composition typically will be from about 10 to about 30% by weight e.g. about 10 to about 20% by weight, of latex.
• the rubber should be one which affords on drying an elastic and relatively tough film, and may be selected from the many natural or synthetic rubbers now available.
• the rubber is a synthetic rubber is may be a neoprene, butadiene-styrene, acrylonitrile-butadiene, ethylene-propylene-diene, polyisoprene, styrene-isoprene, isobutylene-isoprene, polyacrylonitrile, silicone, epichlorohydrin, or polyurethane rubber.
• the rubber is a natural rubber, typically a prevulcanised rubber, and more preferably a natural rubber latex having one or more of the following properties:
• composition of the invention may also include other standard ingredients employed in paint stripping compositions.
• standard ingredients there may be mentioned wetting agents, dyes and other colouring agents e.g. stainers, preservatives and organic solvents in addition to methylene chloride or its equivalent film-dissolving solvent on which the composition is based. All such additional ingredients must, of course, be compatible with the other essential ingredients of the composition and, in particular, must be compatible with the desired emulsified form of the composition. Otherwise, the selection of these conventional ingredients and suitable concentrations for them is believed to be within the competence of the man skilled in the art.
• the composition of the invention may also include a water-miscible organic solvent, in particular an alcohol such as methanol, ethanol or isopropyl alcohol, preferably the later.
• a water-miscible organic solvent in particular an alcohol such as methanol, ethanol or isopropyl alcohol, preferably the later.
• the composition should include an emulsifying agent, which may be nonionic, cationic or anionic, and if desired one or more dyes or stainers.
• composition may include one or more hydrocarbon ingredients, in particular a liquid aromatic hydrocarbon, for example, toluene and/or xylene, and one or more solid, waxy hydrocarbons, for example, as builders.
• hydrocarbon ingredients in particular a liquid aromatic hydrocarbon, for example, toluene and/or xylene, and one or more solid, waxy hydrocarbons, for example, as builders.
• the composition may include one or more gelling or thickening agents of the kind well known to those skilled in the art, for example, hydroxypropyl and/or methyl cellulose.
• the amount of such gelling and thickening agents generally will not exceed about 5% by weight of the total composition, and preferably will be below about 1% by weight of the composition. It is to be understood also that the amount of any such gelling or thickening agent should not be sufficient in any way significantly to contribute to the skin-forming properties of the overall composition.
• the composition of the invention is applied to the surface of a coated e.g. painted or varnished, substrate.
• a coated e.g. painted or varnished, substrate typically, such application may be by means of a brush and typically also a plurality of separately-applied layers of composition may be employed.
• the composition is then left for a period of time to enable a skin to form and the underlying paint or varnish to be softened. Typically, this will take a period of from about 1 to about 2 hours, although longer periods of contact may be desirable when a large number of coats of paint or varnish must be removed.
• the peelable skin is then removed using a scraper, palette knife or similar tool, although actual scraping of the underlying surface should not be necessary.
• the skin is lifted away from the surface together with the softened paint or varnish, and any remaining paint or varnish can then either be removed as dry flakes or by gentle scraping.
• composition was prepared from the following ingredients:
• Two boards were prepared which had ten coats of commercially-available emulsion paint and oil-based paint respectively. After allowing the panels to age for several months, two coats of the above composition were applied and a thick layer built up over the paint. After a short period a flexible rubber-like skin began to form, and after two hours all ten coats of paint from both panels could be removed with the aid of a palette knife. A peelable skin formed which had sufficient strength to remain intact on final removal. Much of the paint adhered to the film, but the remainder could easily be removed as dry flakes by gentle scraping.
• composition was prepared from the following ingredients:
• Example 1 The composition performed as a paint stripper in the same manner as that of Example 1.
• composition was prepared from the following ingredients:
• composition performed as a varnish stripper in the same manner as the paint stripper of Example 1.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Paints Or Removers (AREA)
• Road Signs Or Road Markings (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

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Family Applications (1)

Country Status (11)

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Citations (3)

Family Cites Families (3)

• 1983
  • 1983-11-01 GB GB838329171A patent/GB8329171D0/en active Pending
• 1984
  • 1984-10-23 AU AU34583/84A patent/AU575863B2/en not_active Expired - Fee Related
  • 1984-10-23 NZ NZ209965A patent/NZ209965A/en unknown
  • 1984-10-30 EP EP84307483A patent/EP0144151A1/en not_active Withdrawn
  • 1984-10-30 GB GB08427377A patent/GB2150589A/en not_active Withdrawn
  • 1984-10-31 CA CA000466671A patent/CA1236761A/en not_active Expired
  • 1984-10-31 NO NO844333A patent/NO844333L/no unknown
  • 1984-10-31 DK DK518084A patent/DK518084A/da not_active Application Discontinuation
  • 1984-10-31 ES ES537283A patent/ES537283A0/es active Granted
  • 1984-10-31 PT PT79441A patent/PT79441B/pt unknown
  • 1984-11-01 FI FI844293A patent/FI844293L/fi not_active Application Discontinuation
  • 1984-11-01 GR GR80821A patent/GR80821B/el unknown

Patent Citations (3)

Non-Patent Citations (1)

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